Tape transducing apparatus requires a drive for the tape transport. The tape itself should be driven at a uniform speed past a magnetic transducing head. In one such system, a drive roller is used, which is in engagement with the take-up storage winding and with the pay-out storage winding. In use, the take-up storage winding will increase in diameter as the pay-out storage winding decreases in diameter, so that the overall spacing between a pair of parallel positioned reels, holding the windings, can remain essentially constant, although the position of the free distance of the tape between the two windings shifts laterally between the axes of rotation of the windings. It is necessary to maintain tension on the tape being moved past the transducing head. Some drag force is therefore usually applied to pay-out winding or reel holding the winding. The drag force has to be overcome by the torque of the wind-up mechanism, applied to the take-up winding. If the mechanism driving the take-up winding is in the form of a friction wheel which is in engagement with the winding loops themselves, it is necessary to permit change of position of the respective axes of rotation of the storage windings and of the drive roller.
German Patent Publication De-AS No. 23 50 816 discloses a transport arrangement in which an additional force by means of a biassing spring is applied to the bearing of the take-up winding to provide for reliable operation thereof. The additional force applied by the biassing spring presses the take-up winding into engagement with the drive roller. The pay-out winding itself has no additional force applied thereto.
Application of an additional force to the take-up winding causes additional friction losses which have to be overcome by the torque of the drive unit.